Optimization of lead-free CsSnI3-based perovskite solar cell structure

Abstract Perovskites are considered the most promising material for the latest generation of solar cells. However, due to the presence of lead in their composition, the development of non-toxic Perovskite cells has become an essential goal to enable their large-scale production. In this work, we have simulated, modeled and optimized the structure of a single solar cell that consists of a non-toxic cesium–tin–iodine CsSnI3 Perovskite absorber with a low band gap energy value of 1.3 eV, between TiO2 and PTAA materials as ETL and HTL layers, respectively. A simulation model describing the charge carrier processes and the effect of interface defect density is presented. Several structures based on alternative ETL and HTL materials are proposed. An optimal device structure is proposed based on the results obtained. An efficiency of 19.92% is obtained with V oc = 0.829 V, J sc = 30.68 mA/cm2 and FF = 73.33% using SnO2 and Spiro-OMeTAD as ETL and HTL materials. However, 29.22% is achieved using the optimal structure as the bottom cell in a tandem configuration.